1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* Miscellaneous bits for the netfs support library. 3 * 4 * Copyright (C) 2022 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 */ 7 8 #include <linux/module.h> 9 #include <linux/export.h> 10 #include <linux/proc_fs.h> 11 #include <linux/seq_file.h> 12 #include "internal.h" 13 #define CREATE_TRACE_POINTS 14 #include <trace/events/netfs.h> 15 16 MODULE_DESCRIPTION("Network fs support"); 17 MODULE_AUTHOR("Red Hat, Inc."); 18 MODULE_LICENSE("GPL"); 19 20 EXPORT_TRACEPOINT_SYMBOL(netfs_sreq); 21 22 unsigned netfs_debug; 23 module_param_named(debug, netfs_debug, uint, S_IWUSR | S_IRUGO); 24 MODULE_PARM_DESC(netfs_debug, "Netfs support debugging mask"); 25 26 #ifdef CONFIG_PROC_FS 27 LIST_HEAD(netfs_io_requests); 28 DEFINE_SPINLOCK(netfs_proc_lock); 29 30 static const char *netfs_origins[nr__netfs_io_origin] = { 31 [NETFS_READAHEAD] = "RA", 32 [NETFS_READPAGE] = "RP", 33 [NETFS_READ_FOR_WRITE] = "RW", 34 [NETFS_WRITEBACK] = "WB", 35 [NETFS_WRITETHROUGH] = "WT", 36 [NETFS_LAUNDER_WRITE] = "LW", 37 [NETFS_UNBUFFERED_WRITE] = "UW", 38 [NETFS_DIO_READ] = "DR", 39 [NETFS_DIO_WRITE] = "DW", 40 }; 41 42 /* 43 * Generate a list of I/O requests in /proc/fs/netfs/requests 44 */ 45 static int netfs_requests_seq_show(struct seq_file *m, void *v) 46 { 47 struct netfs_io_request *rreq; 48 49 if (v == &netfs_io_requests) { 50 seq_puts(m, 51 "REQUEST OR REF FL ERR OPS COVERAGE\n" 52 "======== == === == ==== === =========\n" 53 ); 54 return 0; 55 } 56 57 rreq = list_entry(v, struct netfs_io_request, proc_link); 58 seq_printf(m, 59 "%08x %s %3d %2lx %4d %3d @%04llx %zx/%zx", 60 rreq->debug_id, 61 netfs_origins[rreq->origin], 62 refcount_read(&rreq->ref), 63 rreq->flags, 64 rreq->error, 65 atomic_read(&rreq->nr_outstanding), 66 rreq->start, rreq->submitted, rreq->len); 67 seq_putc(m, '\n'); 68 return 0; 69 } 70 71 static void *netfs_requests_seq_start(struct seq_file *m, loff_t *_pos) 72 __acquires(rcu) 73 { 74 rcu_read_lock(); 75 return seq_list_start_head(&netfs_io_requests, *_pos); 76 } 77 78 static void *netfs_requests_seq_next(struct seq_file *m, void *v, loff_t *_pos) 79 { 80 return seq_list_next(v, &netfs_io_requests, _pos); 81 } 82 83 static void netfs_requests_seq_stop(struct seq_file *m, void *v) 84 __releases(rcu) 85 { 86 rcu_read_unlock(); 87 } 88 89 static const struct seq_operations netfs_requests_seq_ops = { 90 .start = netfs_requests_seq_start, 91 .next = netfs_requests_seq_next, 92 .stop = netfs_requests_seq_stop, 93 .show = netfs_requests_seq_show, 94 }; 95 #endif /* CONFIG_PROC_FS */ 96 97 static int __init netfs_init(void) 98 { 99 int ret = -ENOMEM; 100 101 if (!proc_mkdir("fs/netfs", NULL)) 102 goto error; 103 if (!proc_create_seq("fs/netfs/requests", S_IFREG | 0444, NULL, 104 &netfs_requests_seq_ops)) 105 goto error_proc; 106 #ifdef CONFIG_FSCACHE_STATS 107 if (!proc_create_single("fs/netfs/stats", S_IFREG | 0444, NULL, 108 netfs_stats_show)) 109 goto error_proc; 110 #endif 111 112 ret = fscache_init(); 113 if (ret < 0) 114 goto error_proc; 115 return 0; 116 117 error_proc: 118 remove_proc_entry("fs/netfs", NULL); 119 error: 120 return ret; 121 } 122 fs_initcall(netfs_init); 123 124 static void __exit netfs_exit(void) 125 { 126 fscache_exit(); 127 remove_proc_entry("fs/netfs", NULL); 128 } 129 module_exit(netfs_exit); 130